Our goal is to develop a non-powered multi-layer bandage that will provide effective warming therapy to chronic wounds at greatly reduced cost. Ultimately this may bring warming therapy into the nursing home and home care settings where cost is a significant issue, yet such a high percentage of the chronic pressure ulcers and diabetic ulcers must be managed. A large body of literature supports the use of heat to enhance wound healing and reduce the risk of infection. Because therapeutic temperatures are close to the upper limit for safety, it is critical that this heat be delivered at a controlled temperature. Recent development of microencapsulated phase change materials (PCM), which can be impregnated in a variety of materials allows for the development of passive heat storage materials that deliver heat over extended periods at precisely selected temperatures. We will test a variety of PCM formulations, impregnation densities, carriers, bandage, and insulation thickness to evaluate the potential of these materials for incorporation into the warming bandage. A prototype bandage will be assembled and tested for its ability to deliver heat at appropriate temperatures (3 7-42 C) for two or more hours, and increase blood flow. No such device is currently available.